∫dx/(x-a²),令u=x-a²,du=dx=∫du/u=ln|u|+C=ln|x-a²|+C若求∫dx/(x²-a²),令x=asecp,dx=asecptanpdp=∫(asecptanp)/(a²sec²p-a²) dp=a∫(secptanp)/a²tan²p dp=(...